In commercial production, drive shafts, such as vehicle drive shafts, are not uniformly round in cross-section, and are not absolutely straight throughout their length. In addition, each shaft has deviations in wall thickness. Such inhomogeneities in geometry and material result in incongruent mass and rotation centers, resulting in eccentric loading imbalance. This imbalance can cause excessive bearing loads during service, and the bearing loads are aggravated by consequent whirling or whipping of the shaft caused by this unbalanced mass distribution.
With steel shafts, the practice has been to balance the shaft by welding small weights at the end of the shaft. The small balance weights must be attached to the yoke sleeve area at the ends of the drive shaft, because welding of the weights to the thin wall tube can cause thermally induced distortions, resulting in bowing of the shaft that causes an additional imbalance.
With composite drive shafts, such as those formed of fiber reinforced resin, weights cannot be welded to the shaft and thus the shaft must be balanced by other means.
U.S. Pat. No. 4,170,896 describes a method of balancing a high speed propeller shaft through use of self-adhering aluminum tape. In accordance with the procedure described in that patent, the imbalance is measured at a multiplicity of stations along the length of the shaft and the aluminum tape is applied as a continuous strip in a generally zig-zag pattern along the length of the shaft to balance the shaft.